GDAL在靈活的環境中

Question

在應用程序引擎的靈活環境中，我試圖在使用GIS擴展的postgresql數據庫上運行django。可以在本地運行，並最終成功完成雲部署。但是，從雲運行時，我收到「錯誤：服務器錯誤」，並且日誌文件具有以下所示的跟蹤。

實質上，它說它無法讀取文件夾「/env/lib/python3.5/site-packages/django/contrib/gis/gdal」中的文件。該文件夾絕對存在於本地。以下是完整的跟蹤：

Traceback (most recent call last): 
File "/env/lib/python3.5/site-packages/gunicorn/arbiter.py", line 578, in spawn_worker 
    worker.init_process() 
File "/env/lib/python3.5/site-packages/gunicorn/workers/base.py", line 126, in init_process 
    self.load_wsgi() 
File "/env/lib/python3.5/site-packages/gunicorn/workers/base.py", line 135, in load_wsgi 
    self.wsgi = self.app.wsgi() 
File "/env/lib/python3.5/site-packages/gunicorn/app/base.py", line 67, in wsgi 
    self.callable = self.load() 
File "/env/lib/python3.5/site-packages/gunicorn/app/wsgiapp.py", line 65, in load 
    return self.load_wsgiapp() 
File "/env/lib/python3.5/site-packages/gunicorn/app/wsgiapp.py", line 52, in load_wsgiapp 
    return util.import_app(self.app_uri) 
File "/env/lib/python3.5/site-packages/gunicorn/util.py", line 352, in import_app 
    __import__(module) 
File "/home/vmagent/app/mysite/wsgi.py", line 22, in <module> 
    application = get_wsgi_application() 
File "/env/lib/python3.5/site-packages/django/core/wsgi.py", line 13, in get_wsgi_application 
    django.setup(set_prefix=False) 
File "/env/lib/python3.5/site-packages/django/__init__.py", line 27, in setup 
    apps.populate(settings.INSTALLED_APPS) 
File "/env/lib/python3.5/site-packages/django/apps/registry.py", line 108, in populate 
    app_config.import_models() 
File "/env/lib/python3.5/site-packages/django/apps/config.py", line 202, in import_models 
    self.models_module = import_module(models_module_name) 
File "/env/lib/python3.5/importlib/__init__.py", line 126, in import_module 
    return _bootstrap._gcd_import(name[level:], package, level) 
File "/env/lib/python3.5/site-packages/django/contrib/auth/models.py", line 4, in <module> 
    from django.contrib.auth.base_user import AbstractBaseUser, BaseUserManager 
File "/env/lib/python3.5/site-packages/django/contrib/auth/base_user.py", line 52, in <module> 
    class AbstractBaseUser(models.Model): 
File "/env/lib/python3.5/site-packages/django/db/models/base.py", line 124, in __new__ 
    new_class.add_to_class('_meta', Options(meta, app_label)) 
File "/env/lib/python3.5/site-packages/django/db/models/base.py", line 331, in add_to_class 
    value.contribute_to_class(cls, name) 
File "/env/lib/python3.5/site-packages/django/db/models/options.py", line 214, in contribute_to_class 
    self.db_table = truncate_name(self.db_table, connection.ops.max_name_length()) 
File "/env/lib/python3.5/site-packages/django/db/__init__.py", line 33, in __getattr__ 
    return getattr(connections[DEFAULT_DB_ALIAS], item) 
File "/env/lib/python3.5/site-packages/django/db/utils.py", line 211, in __getitem__ 
    backend = load_backend(db['ENGINE']) 
File "/env/lib/python3.5/site-packages/django/db/utils.py", line 115, in load_backend 
    return import_module('%s.base' % backend_name) 
File "/env/lib/python3.5/importlib/__init__.py", line 126, in import_module 
    return _bootstrap._gcd_import(name[level:], package, level) 
File "/env/lib/python3.5/site-packages/django/contrib/gis/db/backends/postgis/base.py", line 6, in <module> 
    from .features import DatabaseFeatures 
File "/env/lib/python3.5/site-packages/django/contrib/gis/db/backends/postgis/features.py", line 1, in <module> 
    from django.contrib.gis.db.backends.base.features import BaseSpatialFeatures 
File "/env/lib/python3.5/site-packages/django/contrib/gis/db/backends/base/features.py", line 4, in <module> 
    from django.contrib.gis.db.models import aggregates 
File "/env/lib/python3.5/site-packages/django/contrib/gis/db/models/__init__.py", line 3, in <module> 
    from django.contrib.gis.db.models.aggregates import * # NOQA 
File "/env/lib/python3.5/site-packages/django/contrib/gis/db/models/aggregates.py", line 1, in <module> 
    from django.contrib.gis.db.models.fields import ExtentField 
File "/env/lib/python3.5/site-packages/django/contrib/gis/db/models/fields.py", line 3, in <module> 
    from django.contrib.gis import forms, gdal 
File "/env/lib/python3.5/site-packages/django/contrib/gis/forms/__init__.py", line 3, in <module> 
    from .fields import (# NOQA 
File "/env/lib/python3.5/site-packages/django/contrib/gis/forms/fields.py", line 4, in <module> 
    from django.contrib.gis.geos import GEOSException, GEOSGeometry 
File "/env/lib/python3.5/site-packages/django/contrib/gis/geos/__init__.py", line 5, in <module> 
    from .collections import (# NOQA 
File "/env/lib/python3.5/site-packages/django/contrib/gis/geos/collections.py", line 11, in <module> 
    from django.contrib.gis.geos.geometry import GEOSGeometry, LinearGeometryMixin 
File "/env/lib/python3.5/site-packages/django/contrib/gis/geos/geometry.py", line 11, in <module> 
    from django.contrib.gis import gdal 
File "/env/lib/python3.5/site-packages/django/contrib/gis/gdal/__init__.py", line 28, in <module> 
    from django.contrib.gis.gdal.datasource import DataSource 
File "/env/lib/python3.5/site-packages/django/contrib/gis/gdal/datasource.py", line 39, in <module> 
    from django.contrib.gis.gdal.driver import Driver 
File "/env/lib/python3.5/site-packages/django/contrib/gis/gdal/driver.py", line 5, in <module> 
    from django.contrib.gis.gdal.prototypes import ds as vcapi, raster as rcapi 
File "/env/lib/python3.5/site-packages/django/contrib/gis/gdal/prototypes/ds.py", line 9, in <module> 
    from django.contrib.gis.gdal.libgdal import GDAL_VERSION, lgdal 
File "/env/lib/python3.5/site-packages/django/contrib/gis/gdal/libgdal.py", line 49, in <module> 
    lgdal = CDLL(lib_path) 
File "/opt/python3.5/lib/python3.5/ctypes/__init__.py", line 351, in __init__ 
    self._handle = _dlopen(self._name, mode) 
OSError: /env/lib/python3.5/site-packages/django/contrib/gis/gdal: cannot read file data: Is a directory 

在ubuntu 16.04上開發。

我在virtualenv裏創建了簡單的「pip install django」，創建了部署時缺少的「django/contrib/gis/gdal」文件夾。我已經嘗試了其他幾種安裝GDAL的方法來確保沒有丟失頭文件。還升級到Google Cloud SDK 171和gsutil 4.27。曾嘗試在requirements.txt中包含GDAL == 2.1.3，但後來發現構建錯誤，因此將其刪除。我也嘗試過「點凍結」，以確保requirements.txt包含所有必需的軟件包。

最後，我從零開始重新開始學習本教程：https://cloud.google.com/python/django/flexible-environment。我沒有在本地postgreSQL數據庫上進行測試，而是直接進入了之前使用過的Cloud SQL實例（需要使用表格）。這次我使用了python2.7。

它仍然在本地運行良好，但現在缺少堆棧跟蹤中的文件夾「/env/local/lib/python2.7/site-packages/django/contrib/gis/gdal」。這是完整的跟蹤：

Traceback (most recent call last): 
File "/env/local/lib/python2.7/site-packages/gunicorn/arbiter.py", line 578, in spawn_worker 
    worker.init_process() 
File "/env/local/lib/python2.7/site-packages/gunicorn/workers/base.py", line 126, in init_process 
    self.load_wsgi() 
File "/env/local/lib/python2.7/site-packages/gunicorn/workers/base.py", line 135, in load_wsgi 
    self.wsgi = self.app.wsgi() 
File "/env/local/lib/python2.7/site-packages/gunicorn/app/base.py", line 67, in wsgi 
    self.callable = self.load() 
File "/env/local/lib/python2.7/site-packages/gunicorn/app/wsgiapp.py", line 65, in load 
    return self.load_wsgiapp() 
File "/env/local/lib/python2.7/site-packages/gunicorn/app/wsgiapp.py", line 52, in load_wsgiapp 
    return util.import_app(self.app_uri) 
File "/env/local/lib/python2.7/site-packages/gunicorn/util.py", line 352, in import_app 
    __import__(module) 
File "/home/vmagent/app/mysite/wsgi.py", line 22, in <module> 
    application = get_wsgi_application() 
File "/env/local/lib/python2.7/site-packages/django/core/wsgi.py", line 13, in get_wsgi_application 
    django.setup(set_prefix=False) 
File "/env/local/lib/python2.7/site-packages/django/__init__.py", line 27, in setup 
    apps.populate(settings.INSTALLED_APPS) 
File "/env/local/lib/python2.7/site-packages/django/apps/registry.py", line 108, in populate 
    app_config.import_models() 
File "/env/local/lib/python2.7/site-packages/django/apps/config.py", line 202, in import_models 
    self.models_module = import_module(models_module_name) 
File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module 
    __import__(name) 
File "/env/local/lib/python2.7/site-packages/django/contrib/auth/models.py", line 4, in <module> 
    from django.contrib.auth.base_user import AbstractBaseUser, BaseUserManager 
File "/env/local/lib/python2.7/site-packages/django/contrib/auth/base_user.py", line 52, in <module> 
    class AbstractBaseUser(models.Model): 
File "/env/local/lib/python2.7/site-packages/django/db/models/base.py", line 124, in __new__ 
    new_class.add_to_class('_meta', Options(meta, app_label)) 
File "/env/local/lib/python2.7/site-packages/django/db/models/base.py", line 331, in add_to_class 
    value.contribute_to_class(cls, name) 
File "/env/local/lib/python2.7/site-packages/django/db/models/options.py", line 214, in contribute_to_class 
    self.db_table = truncate_name(self.db_table, connection.ops.max_name_length()) 
File "/env/local/lib/python2.7/site-packages/django/db/__init__.py", line 33, in __getattr__ 
    return getattr(connections[DEFAULT_DB_ALIAS], item) 
File "/env/local/lib/python2.7/site-packages/django/db/utils.py", line 211, in __getitem__ 
    backend = load_backend(db['ENGINE']) 
File "/env/local/lib/python2.7/site-packages/django/db/utils.py", line 115, in load_backend 
    return import_module('%s.base' % backend_name) 
File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module 
    __import__(name) 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/db/backends/postgis/base.py", line 6, in <module> 
    from .features import DatabaseFeatures 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/db/backends/postgis/features.py", line 1, in <module> 
    from django.contrib.gis.db.backends.base.features import BaseSpatialFeatures 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/db/backends/base/features.py", line 4, in <module> 
    from django.contrib.gis.db.models import aggregates 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/db/models/__init__.py", line 3, in <module> 
    from django.contrib.gis.db.models.aggregates import * # NOQA 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/db/models/aggregates.py", line 1, in <module> 
    from django.contrib.gis.db.models.fields import ExtentField 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/db/models/fields.py", line 3, in <module> 
    from django.contrib.gis import forms, gdal 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/forms/__init__.py", line 3, in <module> 
    from .fields import (# NOQA 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/forms/fields.py", line 4, in <module> 
    from django.contrib.gis.geos import GEOSException, GEOSGeometry 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/geos/__init__.py", line 5, in <module> 
    from .collections import (# NOQA 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/geos/collections.py", line 11, in <module> 
    from django.contrib.gis.geos.geometry import GEOSGeometry, LinearGeometryMixin 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/geos/geometry.py", line 11, in <module> 
    from django.contrib.gis import gdal 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/gdal/__init__.py", line 28, in <module> 
    from django.contrib.gis.gdal.datasource import DataSource 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/gdal/datasource.py", line 39, in <module> 
    from django.contrib.gis.gdal.driver import Driver 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/gdal/driver.py", line 5, in <module> 
    from django.contrib.gis.gdal.prototypes import ds as vcapi, raster as rcapi 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/gdal/prototypes/ds.py", line 9, in <module> 
    from django.contrib.gis.gdal.libgdal import GDAL_VERSION, lgdal 
File "/env/local/lib/python2.7/site-packages/django/contrib/gis/gdal/libgdal.py", line 45, in <module> 
    % '", "'.join(lib_names) 
ImproperlyConfigured: Could not find the GDAL library (tried "gdal", "GDAL", "gdal2.1.0", "gdal2.0.0", "gdal1.11.0", "gdal1.10.0", "gdal1.9.0"). Is GDAL installed? If it is, try setting GDAL_LIBRARY_PATH in your settings. 

任何幫助，非常感謝。

丹

Answer 1

app引擎靈活的環境，配備了這裏列出的C庫：https://cloud.google.com/appengine/docs/flexible/python/runtime

由於GDAL是一個C庫，是不是在標配的運行時間，我必須建立一個自定義環境使用Docker容器。訣竅是在requirements.txt和Python3中將GDAL與必要的Python庫一起安裝，然後通過gunicorn啓動django應用程序。

這裏是我的Dockerfile：

FROM gcr.io/google-appengine/python 

RUN apt-get update && apt-get install -y \ 
    binutils \ 
    gdal-bin \ 
    python-gdal 

# Create a virtualenv for dependencies. This isolates these packages from 
# system-level packages. 
RUN virtualenv /env -p python3.6 

# Setting these environment variables are the same as running 
# source /env/bin/activate. 
ENV VIRTUAL_ENV /env 
ENV PATH /env/bin:$PATH 

# Copy the application's requirements.txt and run pip to install all 
# dependencies into the virtualenv. 
ADD requirements.txt /app/requirements.txt 
RUN pip install -r /app/requirements.txt 
# Add the application source code. 
ADD . /app 

# Run a WSGI server to serve the application. gunicorn must be declared as 
# a dependency in requirements.txt. 
CMD gunicorn -b :$PORT mysite.wsgi 

我的app.yaml：

# [START runtime] 
runtime: custom 
#python 
env: flex 
entrypoint: gunicorn -b :$PORT mysite.wsgi 

beta_settings: 
    cloud_sql_instances: <your-db-instance-identifying-string> 

runtime_config: 
    python_version: 3 
# [END runtime] 

和最小requirements.txt（添加爲需要）：

Django==1.11.4 
mysqlclient==1.3.10 
wheel==0.29.0 
gunicorn==19.7.1 
psycopg2==2.7.3 

希望這有助於某人，

丹